• 전산구조공학
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• 제6권3호
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• pp.89-97
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• 1993

지반위에 얹혀진 구형평판을 에너지 방법으로 해석하는 방법에 대한 일반적인 전개이다. 본 논문에서는 기본적으로 지표면과 평판사이의 접촉응력을 가정한 다음 Boussinesque의 식을 적분하여 지표면 혹은 평판의 처짐을 구하는 방법을 시도하였다. 임의의 차수를 갖는 다항식과 Chebychev다항식으로 접촉응력을 가정할 때 Boussinesque의 식을 적분하는 방법을 서술하고 그 결과를 에너지법에 이용하는 과정을 설명하였다. 해석결과 임의차수를 갖는 다항식을 접촉응력 함수로 적당하지 않고, Chebychev다항식이 합당한 것으로 나타났으나 평판 Boundary의 Stress Singularity를 고려한 함수를 선택하면 훨씬 효과적일 것으로 판단되었다.

• International Journal of Human Ecology
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• 제14권1호
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• pp.1-12
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• 2013

This article examines gender differences in stress levels and coping strategies while using mobile phones. We constructed an e-mail survey to collect data from 1,000 adults in South Korea, and used latent means comparison and multi-group structural regression in structural equation modeling. It was determined that as compared to men, women were more vulnerable to stress. Regarding coping, women used all three coping strategies more equally than men, including active coping, expressive support seeking, and avoidance, whereas men mainly chose active coping; however, there were no significant gender differences in coping outcomes, and both women and men coped effectively by choosing their own personal strategies. We suggested how to reduce stress levels for women through enhancing their self-efficacy, as self-efficacy was shown to reduce stress levels specifically for women. Additionally, based on our findings, we proposed how both men and women could cope more effectively.

• 한국보건간호학회지
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• 제28권2호
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• pp.285-297
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• 2014

Purpose: The purpose of this study was to investigate the structural relationship among the life stress, depression, suicidal ideation of adolescent. Methods: Participants for this study included 285 students from five middle schools located in Seoul and Gyeongsangbukdo, Korea. The SPSS 18.0 program and AMOS 18.0 program were used for analysis of data. Results: The characteristics of this study were to analyze causal relationship with latent variables by considering measurement error and to grasp direct effect, indirect effect and total effect. Life stress and depression were found to be factors influencing suicidal ideation. Depression was a direct factor and life stress was a indirect factor. The effects of depression as a mediator between life stress and suicidal ideation were significant statistically. Conclusion: The findings of this study may provide useful assistance in development of effective nursing interventions for prevention and management of middle school students' suicidal ideation.

• Computational Structural Engineering : An International Journal
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• 제1권1호
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• pp.49-57
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• 2001

This paper presents exact solutions for the modal stress-resultant distributions for vibrating rectangular Mindlin plates involving two opposite sides simply supported while the other two sides free. These exact stress-resultants of vibrating plates with free edges, hitherto unavailable, are very important because they serve as benchmark solutions for checking numerical solutions and methods. Using the exact solutions of a square plate, this paper highlights the problem of determining accurate stress-resultants, especially the transverse shear forces and twisting moments in thin plates, when employing the widely used numerical methods such as the Ritz method and the finite element method. Thus, this study shows that there is a need for researchers to develop refinements to the Ritz method and the finite element method for determining very accurate stress-resultants in vibrating plates with free edges.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.77-81
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• 2006

An attempt has been made to measure existing steel stress using magnetoelasticity. A device has been developed and used for the measurement of magnetism in response to the deformation of a steel bar. The proposed technique can be used for the assessment of existing reinforced concrete structures by the measurements of steel stress embedded inside concrete. A traditional technique requires to break the existing steel bar to measure existing strain. However, the proposed technique is developed to measure the stress without damaging the steel bar. A successful application of magnetoelasticity depends on the establishment of relationship between elastic and magnetic response due to loading. To investigate the correlation between the two, steel bars are loaded in tension under uniaxial loading while the magnetic reading is recorded. Based on the test results, equations are suggested to predict stress for steel bars with different diameters.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.496-499
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• 2006

In this study, a practical method of shrinkage stress analysis on concrete slab in multi-story building is proposed, which considers both internal restraint and external restraint variation resulting from construction sequence. The shrinkage stress due to external restraint is obtained by multiplying relaxation coefficient to elastic shrinkage stress. The additional shrinkage stress due to internal restraint is obtained by residual strain of the elastic analysis. A verification example was analyzed and compared by the proposed method and commercial analysis program that is capable of time-dependent analysis of concrete. The results of 10-story example building show that the internal restraint of reinforcement increases the shrinkage stress considerably at the slabs under loose external restraint.

• 동력기계공학회지
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• 제14권3호
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• pp.71-76
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• 2010

The safety block which prevents drop of laborers at high altitude was analyzed by finite element method. Elastic analysis was done by Ansys ver. 11.0. and tetrahedral meshing was used. As load applied more vertically at the fixed face of saw tooth, the stress concentration became smaller and the load distributed broader. When load worked at saw tooth and the shape was more straight to the direction of load, most stresses except principal stress became smaller. When the area of the load increased, principal stress and equivalent stress could be decreased simultaneously. A principal stress and other various stresses occurred in 3D shape, therefore revised model which has smaller equivalent stress than other models shows excellence on the stability and the credibility.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.230-239
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• 2020

Previous studies have shown disrupted synaptic plasticity and neural activity in depression. Such alteration is strongly associated with disrupted synaptic structures. Chronic stress has been known to induce changes in dendritic structure in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), but antidepressant effect on structure of these brain areas has been unclear. Here, the effects of imipramine on dendritic spine density and morphology in BLA and mPFC subregions of stressed mice were examined. Chronic restraint stress caused depressive-like behaviors such as enhanced social avoidance and despair level coincident with differential changes in dendritic spine structure. Chronic stress enhanced dendritic spine density in the lateral nucleus of BLA with no significant change in the basal nucleus of BLA, and altered the proportion of stubby or mushroom spines in both subregions. Conversely, in the apical and basal mPFC, chronic stress caused a significant reduction in spine density. The proportion of stubby or mushroom spines in these subregions overall reduced while the proportion of thin spines increased after repeated stress. Interestingly, most of these structural alterations by chronic stress were reversed by imipramine. In addition, structural changes caused by stress and blocking the changes by imipramine were corelated well with altered activation and expression of synaptic plasticity-promoting molecules such as phospho-CREB, phospho-CAMKII, and PSD-95. Collectively, our data suggest that imipramine modulates stress-induced changes in synaptic structure and synaptic plasticity-promoting molecules in a coordinated manner although structural and molecular alterations induced by stress are distinct in the BLA and mPFC.

• 가족자원경영과 정책
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• 제14권2호
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• pp.153-176
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• 2010

The purpose of this study was to investigate the relationship between marriage migration females' acculturative stress and marital adjustment, especially the mediating and moderating effects of ego-resilience. The structural equation models were tested by setting marriage migration females' acculturative stress as a prediction variable, their marital adjustment as an outcome variable and their ego-resilience as mediator and moderator variables. The sample consisted of 172 marriage migration females from Busan. I analyzed the data using correlation analysis in order to discover the correlation coefficient of those variables among acculturative stress, ego-resilience and marital adjustment. I used the structural equation model (SEM) for investigating the relationship among acculturative stress, ego-resilience and marital adjustment and for investigating the mediating effects of ego-resilience. I also used multiple group analysis and two way ANOVA to investigate the moderating effects of ego-resilience. The results of structural equation modeling were as follows: first, it was proved that ego-resilience was exerted as a mediating variable, because acculturative stress appeared to affect marital adjustment in relation to ego-resilience. Therefore, marital adjustment was evident when ego-resilience was low. Second, it was proved that ego-resilience was exerted as a moderating variable, because those with low ego-resilience experienced high acculturative stress and low marital adjustment, and those with high ego-resilience experienced low acculturative stress and high marital adjustment. Such findings point out the importance of considering personal characteristics, like ego-resilience, in the relationship between acculturative stress and marital adjustment.

• Geomechanics and Engineering
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• 제28권4호
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• pp.335-346
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• 2022

Buckling failure is a typical slope instability mode that should be paid more attention to. It is difficult to provide systematic guidance for the monitoring and management of such slopes due to unclear mechanism. Here we examine buckling failure as the potential instability mode for a slope above a railway tunnel in southwest China. A comprehensive model test system was developed that can be used to conduct buckling failure experiments. The displacement, stress, and strain of the slope were monitored to document the evolution of buckling failure during the experiment. Monitoring data reveal the deformation and stress characteristics of the slope with different slipping mass thicknesses and under different top loads. The test results show that the slipping mass is the main subject of the top load and is the key object of monitoring. Displacement and stress precede buckling failure, so maybe useful predictors of impending failure. However, the response of the stress variation is earlier than displacement variation during the failure process. It is also necessary to monitor the bedrock near the slip face because its stress evolution plays an important role in the early prediction of instability. The position near the slope foot is most prone to buckling failure, so it should be closely monitored.